1. Field of the Invention
The present invention relates generally to a lifting device and, in particular, to a lifting device for lifting tape cartridges in a cartridges transport system for transport between a storage magazine and a tape streaming device.
2. Description of the Related Art
Date storage and data backup on magnetic tape often requires the use of multiple tape cartridges. These multiple tape cartridges are selectively inserted into and removed from tape streaming device, also referred to as tape recording and playback devices. The utilization of multiple tape cartridges is required for expanded data storage and/or storage of the data from different data backup events. For example, a data backup plan may provide for the use of a different tape for each day of the seek.
Implementation of multiple tape cartridge storage has required a service technician to change the cartridges from the tape streaming device, store the cartridges, and log the event to ensure that the proper cartridge is used at the proper time. Failure on the part of the service technician to change the cartridge at the right time or to use the correct cartridge can result in a failure of the data storage or backup plan.
The increase in data file size and the increased numbers of data files to be stored on a data storage system along with the increased dependance on data is an electronic format has lead to a greater need for reliable high capacity data storage and backup.
The present invention provides a lifter in a transport apparatus for cartridges for automated transfer of tape cartridges between cartridge storing locations and tape streaming devices.
The present invention provides a compact apparatus for transport of a tape cartridge between a tape streaming device and a tape cartridge storage magazine.
The present apparatus provides automated loading, unloading and storage of tape cartridges between multiple storage tape streaming devices and multiple storage locations.
These and other advantages of the present invention are provided in a lifting apparatus having a platform for supporting a cartridge, threaded nuts held in floating supports in the platform, threaded screws through the threaded nuts, and a drive for rotating the threaded screws about their respective axes. The floating supports of the threaded nuts hold the nuts in varying degrees of freedom. For example, one floating support restrains a first nut from lateral and rotational motion, another floating support restrains a second nut from rotational motion and permits motion in one lateral direction, and a third floating support permits both limited rotational and lateral motion of the third nut. This mounting of the threaded nuts prevents binding or jamming and permits a wider range of tolerances to be used in the manufacture of the cartridge transport apparatus.
The floating mounting of the threaded nuts permits the transport system to be of a minimum height, as elongated bearing supports along the length of the threaded screws are not required to prevent jamming and binding of the lifting apparatus. The present lifting device provides maximum utilization of the available height for vertical transport of the cartridge.
A further advantage is that inaccurate synchronization of the threaded screws does not result in jamming of the lifting apparatus. The floating mounting compensates for variations of screw alignment, screw rotation, vibration and shock, and wear to permit the tape transport apparatus to continue working. Lower manufacturing and assembly tolerances also permit the manufacture of the transport apparatus at lower costs.